Such a safety is known from DE PS 1 235 187. Therein, a safety slider displaceable between a safety position and an unsecured position is mounted on a so-called lock. A locking element for blocking or releasing a firing pin nut movably guided in the lock is assigned to a safety slider serving as an actuation element. In this known safety, the locking element is configured as a spherical or roller-shaped rolling element for engagement in a keyway of the firing pin nut. Large operating forces are necessary, however, because the transmission ratio in this case is low and the friction of the cooperating parts is relatively high. Lifting the firing spring nut off of the sear arm against the force of the firing pin spring is associated with a large exertion of force.